The present invention relates generally to cutting apparatus, and more specifically relates to an apparatus for cutting a roofing membrane.
A material commonly applied to building roofs is heat weldable asphalt roofing membrane. This material comes in rolls of various standard widths up to 30 inches and lengths of approximately 30 feet. The asphalt membrane may be applied to a roof surface in a variety of ways. For example, the material may be slowly rolled out onto the roof while applying heat to the underlying surface of the material before it comes in contact with the roof. Alternatively, as disclosed in U.S. Pat. No. 4,743,332 to Black, the membrane may be unrolled on the roof and a hot plate welding device may be moved under the membrane to heat the membrane and weld it to the roof surface.
Because roof surfaces may be of any dimension and may have upstanding structures which interfere with the application of the roofing membrane, it may be necessary to apply a length of roofing membrane that has a width smaller than a standard membrane width. Thus, it becomes necessary to cut the asphalt membrane so that the membrane has the required width.
Heretofore, lengths of roofing membrane have been cut using knives. The roofer must unroll the entire length of the membrane and mark the line to be cut with a chalk line. Knives are then used to cut along the chalk line. This method has the disadvantage of being not easily performed, and it is difficult to maintain a straight cut along the asphalt membrane, especially if the cut is to be made along the entire length of the membrane roll. Moreover, since the knife may extend entirely through the membrane and cut the surface underlying the membrane, the membrane must be moved away from the surface to which it is to be applied to avoid damage to underlying roof layers. This manual method of cutting the membrane is very time consuming, often requiring about one half hour to cut the length of the roll.
Accordingly, the present invention provides an apparatus whereby a roofing membrane may be easily cut to provide a non-standard width along the entire length of the membrane. Moreover, the present invention provides an apparatus whereby a straight cut in a roofing membrane may be easily made along its entire length, without damaging roofing layers underlying the membrane. It has been found that the present invention reduces the time to cut an entire length of roofing membrane from one half hour to about 1 1/2 minutes.